Obstructive sleep apnea (OSA) is a major public health concern driven by rising rates of obesity in the United States. Positive airway pressure (PAP) therapy is the treatment-of-choice and ?gold standard? for individuals with moderate-to-severe OSA. Regular and sustained PAP use can reduce risk for subsequent disease and improve quality of life. Nevertheless, PAP adherence rates are abysmally low. Nearly 25% discontinue use within two weeks and 50% by one year. Most PAP adherence programs do not address the self-management skills and strategies that promote adherence and are often too costly and complex to integrate into overburdened clinical environments. Furthermore, they do not leverage opportunities to change lifestyle behaviors that occur across the 24h spectrum (i.e., sleep hygiene, sedentary behavior, physical activity), which have promise to improve OSA symptoms and PAP adherence. Our team has previously developed and successfully tested BeWell24, a multicomponent smartphone ?app? that uses evidence-based behavior change strategies to improve sleep, sedentary, and physical activity behaviors. We will enhance this app to create SleepWell24. Enhancements will include: (1) specific behavior change strategies from the evidence-based Sleep Apnea Self-Management Program to promote PAP adherence; (2) an interface for exchange of patient data to facilitate patient-provider communication on treatment progress; and (3) real-time feedback via wireless integration with a consumer-based PAP machine and wearable sensor. All aspects of this work, from app design/development to program delivery and evaluation, will be embedded within the Mayo Clinic Arizona Center for Sleep Medicine and associated primary care based clinics to enhance likelihood of future clinical adoption. We will test the effects of SleepWell24 in newly prescribed PAP users and gather data on the feasibility and acceptability of using SleepWell24 compared to a usual care control group. We will conduct a pilot randomized controlled trial with participants randomly assigned to (1) SleepWell24; or (2) usual care for 60 days post-PAP prescription. We will track recruitment/retention rates, app usage statistics (e.g., min/day of use, use of specific app functions), obtain validated measures of treatment satisfaction among patients, patient-provider communication, and conduct qualitative interviews among clinical providers and patients. We will objectively measure PAP adherence to test whether the SleepWell24 group will have more hours/night of PAP usage compared to the usual care group. In an exploratory fashion and driven by our newly developed conceptual model, we will also examine the effect of SleepWell24 on selected treatment outcomes (weight, daytime sleepiness, cognitive impairment, and health-related quality of life) and evaluate putative social cognitive and lifestyle behavior mediators of SleepWell24 on PAP adherence. This study represents an important step in identifying a scalable solution to poor PAP adherence rates and will provide the scientific basis to justify a larger clinical trial.